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5338 Uppsatser om Electrical Power Systems - Sida 15 av 356
Prefabricerade ramper i stålfiberbetong
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Metoder för kartläggning och analys av nätförluster i lågspänningsnät
An important process for grid companies in order to reduce power losses in electricity distribution grids is to figure out where and how they appear. This report describes the factors that cause power losses in low voltage distribution grids and methods for how they could be measured and analyzed. Measurement data for consumed and injected energy were collected for twelve low voltage distribution grids owned by Gävle Energi AB in order to analyze the size of the power losses and how the measurement uncertainty affects the collected data. Then models of three of the grids were created in MATLAB in order to analyze the data and the power losses were calculated to be compared to the collected data. Curve fitting were also used as a method in order to analyze the power losses from collected data.The results show that the losses in the studied grids are low.
Att övervinna barriärer för kunskapsåterföring - En fallstudie av NCC
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Stålfiberarmerad betong - En ekonomisk jämförelse
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Nya inslag i bostadspolitiken konsekvenser för Helsingborg
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Utveckling av en metod för avvikelsehantering i byggföretag
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Framtidens byggarbetsplats. Organisation och Kompetens
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Verksamhetsstyrningens inverkan på målprioritering - En kvalitativ fallstudie av två vårdcentraler i Stockholms läns landsting.
This study aims to examine the effect management control systems have on which goals health centers prioritize. The management control systems of one privately owned and one publicly owned health center have been studied through a qualitative case study. Robert Simons (1995) framework with four levers of control (diagnostic control systems, interactive control systems, belief systems and boundary systems) has been used to structure the study. For both health centers we found a conflict of interest mainly between the diagnostic control system and the beliefs system, where the diagnostic control system is biased towards quantitative goals and the beliefs system is mainly biased towards qualitative goals. However, despite the unbalanced levers of control the studied health centers have been able to reach a well functioning compromise between quantitative and qualitative goals..
Ikeas retuscherade kvinnor : En kvalitativ studie av Ikeas val att retuschera kvinnor i den Saudiska Ikea-katalogen
On the first of October 2012 the media reported that the women in the Ikea cataloguehad been airbrushed in the Saudi edition. Initially the blame was put on either theSaudi government the Islamic culture or the Saudi franchise. In the end it wasrevealed that the Swedish company Inter Ikea Systems had the full responsibility forIkeas actions and therefore was the culprit behind the airbrushing. On whoseinitiative or why the airbrushing was done the media never found out. These areanswers only Ikea has, although they remain unresponsive to these questionsthroughout the news portrayal.This study methodology uses a qualitative content analysis as framework to furtherinvestigate the news media with support of theoretical perspectives such as mediatheory, power relations and cultural differences.
Avbrottsfri Kraft med användning av ultrakondensatorer
The supply of uninterruptible power can be applied to many areas wherecontinuous operation is highly prioritized.The application of uninterruptible power for motor operation is facilitatedusing a frequency converter. Direct current operated frequency converters canbe applied directly to the power reserve which removes the need for additionalpower-converting.Batteries have long constituted the power reserve but advancements inthe development of ultracapacitors have created a viable substitution. Ultra-capacitors have high energy storing capabilities and can be applied to highpower applications.Maxwell is a leading manufacturing company of ultracapacitors and pro-vide different modules with built-in solutions for voltage balancing. Unevenvoltages between series-connected capacitors is a phenomenon caused by vary-ing capacitance. A configuration containing Maxwell?s 56V module is createdand constitutes the power reserve in the simulations.The discharge simulation shows a significant current that could damagethe system.
Anställdas attityd till miljön och miljöledningssystemet: ALSTOM Power Sweden AB
Today environmental management systems (EMS) are common documents (more correctly, a combination of documents) that direct, steer and regulate environmental efforts within many companies. The intention of EMS is that its guidelines are reflected in how the employee carries out his everyday work tasks. This study aims to illuminate the attitudes that exist regarding the EMS at ALSTOM Power Sweden. By using questionnaires and interviews as a method to communicate with employees,a study of the existing attitudes regarding the EMS was carried out. The results were analyzed categorically and statistically and show that there are consistent attitudes among employees, but that there are also inconsistent attitudes.
Dialog, maktrelationer och våld : En kvalitativ studie om maktrelationer i klassrummet och våld som uttryck för motstånd
Violence against teachers in Swedish schools, according to recent reports has increased and there have been many studies to investigate the situation for teachers. The surveys show that teachers are especially vulnerable to students. This study aims to examine the relationship between a number of teachers and their students to study the power relations that exist in the classroom. This is to see what violence is an expression of and also how violence is perceived by the teachers. The issues that are central in this study are:What is the importance of dialogue in the relationship between these teachers and their students?Is there power relations between teachers and their students?What is the violence against teachers and expression of?Is there any connection between dialogue, power relations and violence?The theories of the materials in this study was analyzed using power relations theories of the historian of ideas Michel Foucault and Philosophy Doctor Anders Persson, who to some extent has his theoretical basis in Foucault?s power relations.
Skador på parkeringsdäck av betong. Skadeorsaker och reparationsåtgärder
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Utveckling av erfarenhetsåterföring - I samarbete med AF Bygg Göteborg AB
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.
Undersökning av linjespänning vid återmatande bromssystem i spårvagn M31
This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.
In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.
Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.
The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.